1. Field
The present disclosed aspects relates generally to wireless network protocols, and more specifically to method and apparatus for resolving blinded-node problems in wireless networks.
2. Background
The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.11 Wireless Local Area Network (WLAN) Standards have gained significant popularity in recent years. This family of standards covers a wide range of wireless networks with various system designs that are meant to handle a different traffic and user scenarios. Many other wireless networks designs, such as residential and commercial wireless networks, mesh networks, ad hoc networks, wireless sensor networks, etc., are based on the IEEE 802.11 standards.
In IEEE 802.11-based wireless networks, control messages such as request to send (RTS)/clear to send (CTS) are used by the various nodes of the network to reserve access to the wireless medium. The RTS/CTS mechanism is used to minimize or eliminate interference and collisions between the nodes of the network that wish to communicate over the medium. However, one scenario in which medium reservation using RTS/CTS exchanges breaks down occurs when one or more nodes are not able to detect the RTS/CTS exchanges because the node is listening to the wrong RTS/CTS exchange. This scenario is referred to as the “blinded node problem,” in line with such widely accepted terms as the hidden node problem and the exposed node problem. This problem can take place in all communications systems in which the RTS/CTS control packets are used to reserve the medium. The blinded node problem can cause degradation of both the throughput and delay performance of the wireless network, both locally and network-wide.
There is therefore a need in the art for a solution to resolve the blinded node problem that occurs in wireless networks that rely on the RTS/CTS wireless medium reservation mechanism.